Portable thermal unit



Sept. 15, 1964- J. o. EWING 3,148,513

PORTABLE THERMAL UNIT Filed April 2, 1962 4 Sheets-Sheet lHHHIHHHHHHHHHHHUL James 0. E wing IN VEN TOR.

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Sept. 15, 1964 J. o. EWING PORTABLE THERMAL UNIT 4 Sheets-Sheet 2 FiledApril 2, 1962 Sept. 15, 1964 J. o. EWING PORTABLE THERMAL UNIT 4Sheets-Sheet 3 Filed April 2, 1962 James 0. Ewing INVENTOR.

oil/M FM Sept. 15, 1964 J. o. EWING PORTABLE THERMAL UNIT 4 Sheets-Sheet4 Filed April 2, 1962 James 0. Ewing 1N VEN TOR.

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Attorneys M No mm mm *0 his! i United States Patent 3,148,513 PORTABLETHERMAL UNIT James 6. Ewing, R0. Box 6037, Nashville, Tenn. Filed Apr.2, 1962, Ser. No. 184,273 4 Claims. (Cl. 62-160) The present inventiongenerally relates to a portable thermal unit and specifically includesvarious improvements over that construction disclosed in prior Pat. No.2,959,027, issued November 8, 1960, for Combination Evaporator-CondenserAssembly With Concentric Tubular Construction.

The primary object of the present invention is to provide a portablethermal unit having a flexible tubular concentric assembly employed asone heat exchange unit combined with a compressor unit and a second heatexchange unit together with an automatic reversing valve which isautomatically controlled thereby providing for automatic cycling formaintaining the temperature of a fluid solution enclosing the flexibleheat exchange unit between predetermined high and low temperatures.

Another important object of the present invention is to provide aportable thermal unit having a flexible tubular concentric heat exchangeunit together with a safety pressure bypass line.

Still another object of the present invention is to provide an automaticportable thermal unit especially constructed for liquid processtemperature control and includes a circulating pump which facilitatesthe use of the portable thermal unit of the present invention in an opensink system or jacket tank arrangement and eliminates summer-winterchangeover arrangements inasmuch as the reversible compression expansioncycle employed in the thermal unit may add heat to the liquid used inthe process or take heat away from the liquid thereby maintaining atemperature control automatically within predetermined high and lowtemperatures. The unit is also provided with a programming timer byvirtue of which the unit may be placed into operation at predeterminedintervals or at any given time. The unit is also provided with signallights for indicating the phase of operation of the unit which will warnan operator that too much freshening water is being introduced into asink system for example and will otherwise keep the operator fullyinformed as to the cycle of the unit.

Other features of the present invention will reside in the simplicity ofconstruction, compactness of the components, ease of control, adaptationfor various uses, simplicity of operation effected by the automaticcontrol assembly, dependable and generally inexpensive to manufacture.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part thereof, whereinlike numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of the portable thermal unit of thepresent invention illustrating the assembly thereof with an open sink ortank;

FIGURE 2 is a longitudinal sectional view of the cabinet illustratingthe compressor assembly, the control assembly and the heat exchange unitdisposed in the cabinet;

FIGURE 3 is a top plan view with the cabinet illustrated in section anddisclosing further structural details of the assembly;

FIGURE 4 is a detailed sectional view taken substantially upon a planepassing along section line 44 of FIGURE 2 illustrating the constructionand assembly of the reversing valve;

FIGURE 5 is a detailed sectional view taken substantially upon a planepassing along section line 5-5 of FIGURE 3 illustrating the T-connectionand restrictor tube associated therewith;

FIGURE 6 is a longitudinal detailed sectional view illustrating theconstruction of the flexible heat exchange unit;

FIGURE 7 is a transverse sectional view taken substantially upon a planepassing along section line 7-7 of FIGURE 6 illustrating the flexibleheat exchange unit;

FIGURE 8 is a longitudinal sectional view of a connection with the heatexchange unit disposed in a cabinet; and

FIGURE 9 is a schematic view illustrating the relationship of thecomponent parts of the portable thermal unit.

Referring now specifically to the drawings, the numeral 10 generallydesignates the portable thermal unit of the present invention in whichis incorporated a reversible refrigeration system which includes acommercially available compressor and motor assembly 12 that may behermetically sealed and supported on a suitable base 14. The base 14 maybe of any desired construction and any suitable shock absorbingequipment may be employed in conjunction with the compressor and motorassembly. Enclosing the motor compressor unit 12 is a cabinet 16 havingreversely bent end portions 18 that support and retain screens 20 and 22respectively which form closures for the open ends of cabinet 16 butwhich enable circulation of air therethrough.

Also disposed in the cabinet 16 is a looped tube type of heat exchangeunit generally designated by the numeral 24 and which includes fins 26and a looped tube 28 for purposes of providing good heat exchangerelation between fluid passing through the looped tubes 28 and airpassing over the surfaces of the tubes 28 and the fins 26. Disposedwithin the casing 16 is a shroud 30 receiving a fan and motor assembly32 for forcing air over the heat exchange unit 24. Suitable supportbrackets 34 are provided for the heat exchange unit 24 and also serve tosupport the shroud 30 in position. The motor 32 is electricallyassociated with the compressor and motor assembly 12 so that the motorand compressor assembly 12 and the fan motor 32 will be operatedsimultaneously.

Also disposed interiorly of the casing 16 is a program timer assemblygenerally designated by numeral 36 and a solenoid operated reversingvalve generally designated by numeral 38 which is operated in responseto the program timer 36. On one wall of the casing or housing 16 theprogram timer is mounted on a removable panel 40 as illustrated inFIGURE 1 and includes a circular dial-type indicator 42 associated withan index line 44 by virtue of which the programming of the operation ofthe unit may be preset. Also, signal lights 46 and 48 are mounted in thepanel 4% for indicating the cycle of operation of the unit. The signallight may be of various colors to indicate to the operator theparticular phase of a cycle of the unit. For example, one signal lightmay be blue in color to indicate that the system is in a cooling phaseand a yellow signal light may be used in the other light for indicatingthat the system is in a heating phase or cycle. This will indicate tothe operator that certain conditions exist which need correcting. Forexample, excessive operation in the cooling phase or cycle wouldindicate to the operator that an excessive quantity for freshening wateris being supplied to the system.

As illustrated in FIGURE 1, the portable thermal unit is illustrated inuse in combination with an open sink or tank 50 having a liquid processsolution 52 therein which may be Water or any liquid desired to have asubstantially constant temperature. The tank or open sink 50 is providedwith a pair of adaptor nipples 54 and 56 attached thereto to which isattached flexible hoses 58 and 60 of transparent plastic material withconventional hose clamp 62 securing the hoses in fluid-tight relationthereby enabling circulation of the liquid in the tank.

The plastic tubes 58 and 60 are communicated with a motor and pumpassembly 64 carried by an extension plate 66 on the base 14. The tube 58is connected to the pump unit 64 by a short crossover tube 68 and thetube 60 is also connected with the pump unit 64 by a short tube 70. Themotor and pump unit 64 is of conventional construction and circulatesthe liquid 52 in the tank or sink in such a manner that continuouscirculation is provided during operation of the portable thermal unit.An electrical conductor 72 interconnects the motor and pump unit 64 withthe electrical control for the portable thermal unit thereby operatingthe pump and circulating the liquid 52 during operation of the portablethermal unit.

The length and orientation of the flexible tubes 58 and may vary as maythe point of connection to the open sink or tank. Preferably, the tubes58 and 60 are constructed of transparent plastic material which areimpervious to adverse action by acidic or alkaline solutions.

As illustrated schematically in FIGURE 9 and in detail in FIGURE 5, theplastic tube 58 terminates adjacent a T-connection generally designatedby numeral 74 which includes a T-coupling 76 having longitudinallyaligned externally threaded end portions 78 and 80 and a branchexternally threaded portion 82 that is connected with a tube 84 byvirtue of a clamp nut 86 and a flared end portion 88. The end portion 78is connected to an adaptor nut 90 which is internally threaded forthreaded engagement with the end portion 78. Also, the threaded nut 90has an externally threaded shoulder 92 integral therewith and alongitudinal flared extension 94. A retainer nut 96 is internallythreaded and engages the threaded shoulder 90 and has a recess 98therein receiving a tube 100 thus sealing the tube 100 to the nut 90 andthus to the T- shaped coupling 76. A concentric tube 102 is disposed inconcentrically spaced relation to the tube 100, the extension 94, theinternal bore 104 of the nut 90 and the internal bore 106 of theT-coupling 76. The bore 106 terminates in a shoulder 107 which defines abore 109 which closely receives the inner concentric tube 102 thussealing the tube 102 in relation to the T-coupling 76 while theconcentric space between the concentric tube 102 and the internal bore106 is communicated with the bore 108 extending through the branchportion 82 for communication with the tube 84.

Communicating with the threaded end portion 80 is a tube 110 having theend portion thereof flared as at 112 for receiving an internallythreaded clamping nut 114. r

The inner tube 102 extends into the tube-110 in sealed relation theretoand a short capillary tube 116 is disposed in the end portion of thetube 102 thus forming a restriction between the interior of the tube 110and the interior of the tube 102. For rigidifying this area and forminga backing for the tube 110 and the tube 102 for retaining the capillarytube 116 in sealed relation thereto, there is provided a rigidifyingsleeve 118 enclosing a portion of the tube 110 throughout thelongitudinal extent and beyond the ends of the capillary tube 116. Thiswill provide a secure and rigid assembly for supporting the capillaryrestrictor 116 in position and provide a sealed connection between tube110 and the tube 102.

The tube 110 extends into a larger tube 120 as illustrated in FIGURE 8and the terminal end portion of the tube 110 as indicated by numeral 122is disposed in spaced relation to the internal diameter of the tube 120.The end portion of the tube 120 is provided with a reduced portion 124which engages and is sealed to the tube 110 thus forming an expansionarea in the tube 120 which is connected with one end of the tubing 28 inthe heat exchange unit 24. The other end of the tubing 28 is connectedwith a fitting 126 on the reversing valve 38. The tube 84 is connectedto another fitting 128 on the reversing valve 38. A third fitting 130 onthe reversing valve 38 is communicated with a tube 132 connected withthe compressor motor assembly 12 which may be considered the outlet ordischarge side of the compressor unit 12. A fourth fitting 134 on thereversing valve 38 is communicated with a tube 136 extending to theinlet side of the motor compressor unit 12. A bypass line or tube 138intercommunicates the tubes 132 and 136 respectively to provide a bypassfor the motor compressor unit for purposes of safety. An adjustableneedle control valve 140 is provided in the bypass line 138 for varyingthe pressure at which the discharge side 132 of the motor compressorunit will be bypassed back to the inlet side 136.

Disposed in the tube 60 is a sensing bulb 142 of any suitableconstruction and the bulb 142 is connected with a capillary tube 144which terminates in a thermostatic control device 146, whereby thesensing bulb 142 will indicate to the thermostatic control 146 thetemperature of the liquid being circulated in the tube 60 thus servingto operate the portable thermal unit accordingly. Disposed in the tube58 is a heat exchange unit 148 which is of a flexible nature and thedetails of which are illustrated in FIGURES 6 and 7 respectively. Thetube 102 as illustrated in FIGURE 5 continues into the heat exchangeunit as illustrated in FIGURE 8 and the tube 100 is connected to aflexible tubular unit 150. The flexible tubular unit 150 is of a bellowstype tube having serpentine convolutions extending throughout the lengththereof and having an end cap 152 associated therewith. A protectivewoven screen 154 is provided on the bellows tube 150 thereby serving toprotect the bellows tube 150 from damage such as puncture or the like.

The inner tube 102 extends concentrically of the bellows tubehereinafter called the outer tube 150 and a restrictor capillary tube156 is provided in the end of the tube 102 and a short tube 158 enclosesthe outer surface of the tube 102 which receives the capillary tube orrestrictor 156 therein. The tube 158 may be deformed peripherallyinwardly as at 160 for securing the tube 158,

. tube 102 and capillary tube 156 in position. At the other end of thetube 158, a longitudinal extension tube 162 is connected to the tube 158and a short capillary tube 164 is disposed in the end of the extensiontube 162. The connection between tubes 164, 162 and 158 is similar tothe connection between tubes 156, 162 and 153. The extension tube 162terminates in spaced relation to the cap 152.

Disposed in enclosing relation to the extension tube 162 and the majorpart of the tube 158 is a tubular spiral coil 166 forming a capillarytube which may be in contacting relation to the flexible outer tube 150.The inner end of the coil 166 is provided with an inwardly extending endportion 168 terminating in an open end 170 interiorly of the tube 158inwardly of the capillary tube 156 and facing capillary tube 164.Disposed in spaced relation to the open end 170 of the end portion 168of the coil 166 is a ball check valve 172 which engages a ball valveseat formed by an inward deformation or rib 1'74 formed in the tube 158whereby the ball valve 172 may move from a position engaging the openend 170 of the inner end portion 168 of coil 166 or a position engagingthe valve seat 174 thus forming a selective closure for these twocomponents.

FIGURE 3 discloses the manner in which the tubes 58 and 60 are closed toprevent leakage and also discloses the relationship of the components ofthe invention.

The reversing valve is solenoid operated and instantly reverses and isthe type manufactured by Ranco Incorporated of Columbus, Ohio as ModelNo. V26.

The operation of the compressor unit and the heat exchange units aregenerally the same as that defined in prior Patent No. 2,959,027 withthis construction being capable of enabling flexibility of the heatingunit disposed in the concentric tube assembly and providing specificdetails of construction which are novel together with a novel controlapparatus for the device whereby a reversing of the system isautomatically carried out by a timer or programmer which also is acommercially available item.

Assuming that the refrigeration system is operating for cooling theliquid solution in the tank, the compressor unit 12 will operate anddischarge hot refrigerant gas through the heat exchange unit 24 actingas a condenser for cooling liquefaction in the usual manner and thenpass through the inner tubular member until it engages the ball valve162 which will cause the liquid refrigerant to enter the open end of thespiral coil capillary tube 166 and subsequently be discharged into theend of the outer tubular member 150 whereby the expansion therein willcause absorption of heat from the liquid solution which is surroundingthe flexible outer tubular member 150. The evaporated refrigerant willthen pass between the tube 150 and the tube 102 back to the intake sideof the compressor through the reversing valve 38 thus completing thecycle.

When employed to give up or add heat to the liquid solution, thereversing valve is oriented so that hot gaseous refrigerant will bedischarged through the line 84 into the space between tubular member 102and tubular member 100 and ultimately pass longitudinally around theexterior of the tubular member 102 whereby the exchange unit 148 acts asa condenser until the refrigerant gas is cooled and it reaches the outerend of the outer tubular member 150. The pressure and movement of thecondensed refrigerant will move the ball valve 172 away from the valveseat as the refrigerant enters the end of the tubular extension 162thereby permitting passage of the refrigerant through the restrictions164 and 156 which maintain a pressure differential. The ball valve 172will then normally close the open end of the capillary tube or coil 166.The condensed refrigerant will then pass through the tube 102, throughthe T-coupling and into the heat exchange unit 24 which then acts as anevaporator. The liquified refrigerant will be evaporated in the heatexchange unit 24 and discharged back into the intake side of thecompressor unit.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

What is claimed as new is as follows: I

1. A portable thermal unit including a reversible refrigeration systemcomprising a compressor having an intake and outlet, a first heatexchange unit, a second heat exchange unit, one of said units includinga flexible outer tubular member and a flexible inner tubular memberconcentric therewith, the inner tubular member of said one unit beingconnected with the other heat exchange unit, a reversing valveselectively interconnecting the compressor intake and outlet with theouter tubular member of the one unit and with the other heat exchangeunit, and capillary tube means intercommunicating the units andrestricting flow of refrigerant so that the same may expand forabsorbing heat, the outer end of the outer tubular member being closedfor flow and expansion of the refrigerant from the inner tubular memberto the outer tubular member, said outer tubular member being in the formof a flexible bellows member, and a protective wire woven casingenclosing the bellows member for preventing damage thereto.

2. The structure as defined in claim 1 wherein said reversing valve andcompressor are thermostatically controlled, and a bypass line for therefrigerant to protect the compressor from excessive head pressures.

3. The structure as defined in claim 1 wherein said capillary tube meansincludes a check valve in the inner tubular member for prohibiting flowof liquified refrigerant from the outer end thereof, and a spiralcapillary tube having one end communicating with the inner tubularmember on the upstream side of the check valve and the other end of thetube being communicated with the interior of the tubular member forexpansion of the refrigerant.

4. The structure as defined in claim 3 wherein said spiral capillarytube includes an inner end disposed interiorly of the inner tubularmember on the upstream side of the check valve, said check valve beingin the form of a freely movable ball valve movable between the inner endof the coil tube and a valve seat whereby gaseous refrigerant may passoutwardly between the inner tubular member and the outer tubular memberand back into the interior of the inner tubular member past the ballvalve for heating the outer tubular member.

References Cited in the file of this patent UNITED STATES PATENTS2,153,335 Martin Apr. 4, 1939 2,762,209 Bennett Sept. 11, 1956 2,959,027Ewing Nov. 8, 1960

1. A PORTABLE THERMAL UNIT INCLUDING A REVERSIBLE REFRIGERATION SYSTEMCOMPRISING A COMPRESSOR HAVING AN INTAKE AND OUTLET, A FIRST HEATEXCHANGE UNIT, A SECOND HEAT EXCHANGE UNIT, ONE OF SAID UNITS INCLUDINGA FLEXIBLE OUTER TUBULAR MEMBER AND A FLEXIBLE INNER TUBULAR MEMBERCONCENTRIC THEREWITH, THE INNER TUBULAR MEMBER OF SAID ONE UNIT BEINGCONNECTED WITH THE OTHER HEAT EXCHANGE UNIT, A REVERSING VALVESELECTIVELY INTERCONNECTING THE COMPRESSOR INTAKE AND OUTLET WITH THEOUTER TUBULAR MEMBER OF THE ONE UNIT AND WITH THE OTHER HEAT EXCHANGEUNIT, AND CAPILLARY TUBE MEANS INTERCOMMUNICATING THE UNITS ANDRESTRICTING FLOW OF REFRIGERANT SO THAT THE SAME MAY EXPAND FORABSORBING HEAT, THE OUTER END OF THE OUTER TUBULAR MEMBER BEING CLOSEDFOR FLOW AND EXPANSION OF THE REFRIGERANT FROM THE INNER TUBULAR MEMBERTO THE OUTER TUBULAR MEMBER, SAID OUTER TUBULAR MEMBER BEING IN THE FORMOF A FLEXIBLE BELLOWS MEMBER, AND A PROTECTIVE WIRE WOVEN CASINGENCLOSING THE BELLOWS MEMBER FOR PREVENTING DAMAGE THERETO.